World Without End
by Lady of Sandwiches
Summary: Castiel never wanted any of this. He had only wished to stop Raphael. Sam/Castiel, S6 AU. *SEE PROFILE FOR MORE INFO*


It wasn't supposed to be like this. Castiel had only wanted to protect his Father's final creation, to stop Raphael from reigniting the spark of war, to ensure that Sam's sacrifice would not be in vain. To do the right thing, as he had been taught. If Castiel had inherited Winchester morals, he had also inherited Winchester luck.

Things had been going badly, very, very badly. While many of his brothers and sisters chose to fight with him, many more looked to Raphael to lead them. It made sense, after all - an Archangel over a fallen and subsequently newly-restored one. Heaven was experiencing a crisis of faith, and reverting to its fundamentals. Castiel thought it was a remarkably human thing to do.

Raphael was strong, and persuasive. He comforted the masses with talk of God's Plan. Castiel's steadily dwindling numbers were not enough to stop him, nor were the holy weapons that Balthazar had stolen. So he was forced to recruit elsewhere, namely, Hell. It was the only viable option at this point. That didn't mean Castiel had to like it.

Hell had broken Dean, had taken Sam. Castiel didn't want anything to do with it. But down he went, seeking a demon named Crowley.

He found Hell ripped apart, Crowley dead, and in the middle of a putrid, festering battlefield -

"Sam!"

Bloody hands, bloody lips, golden eyes. He had escaped the Cage, and claimed his birthright. Perhaps Lucifer had assisted him. "Cas," he said, and embraced the angel with trembling arms. Sam's breath was sweet, cloying, and hot against his ear. Castiel could not have pulled away if he tried. He was not afraid, merely sorrowful. Hell had taken everything that was good about Sam - his kindness, his empathy, his _humanity -_ and stripped it away methodically, leaving the Boy King behind. He supposed that he should, for all intents and purposes, consider Sam dead. But he didn't. Accepting that felt too much like failure. As long as Sam was alive, Castiel could help him, could _save_ him, could restore him to the man he was before, like he deserved.

Still, Castiel would rather have worked with a trusted ally than a power-hungry demon.

And, for a while, it worked. Sam was smart, he was powerful. He was a born leader, a brilliant commander. By all rights, he should have been leading the war against Raphael. However, he deferred to Castiel. He gathered all his demons, swayed more than a few of Raphael's angels to their side, but he gave total control to Castiel.

"You're our leader, Cas," Sam had said when Castiel questioned him about it, "and I don't exactly have the best track record. If you left it up to me, I'd just fuck everything up. Besides," and then he'd look down, as if embarrassed, "at the end of the day, I'm still a demon, and you're still an angel." Castiel was confused - that explained nothing. But it was the only answer Sam would give, so Castiel did not press the issue. However, he couldn't shake the feeling that something was wrong.

The war continued.

When they had first met, Sam had been in awe of Castiel. It had not been strange - Sam back then had been a very devout man, despite his line of work and his extracurricular activities. Over the course of their friendship, his attitude had evolved from hero worship into mutual respect. What was strange was that it seemed to have devolved back into one-sided reverence. "Amazing," he'd say, eyes wide and shining. "Amazing." This Sam was more physical than the other, too. He wouldn't hesitate to brush against Castiel's arm, or to take Castiel's hand in his, or to embrace him. Sam would envelop him in his arms, gently, delicately, as if he were holding a holy relic. Worship was in his every gesture, devotion in his voice when he whispered "I love you." Castiel did not think much of it.

Perhaps he should have. When Sam came to him bearing an ancient tome and declaring that he wanted Castiel inside of him, he thought that he probably should have paid more attention to his second in command.

"Not, like, sexually," Sam said, his anticipation overriding any awkwardness, "I want to be your vessel."

"Sam, it is impossible. I am not compatible with your bloodline. You were created to be Lucifer's - "

"Yeah, I know, but we can change that, look," and he shoved the book in Castiel's face, a book of very arcane and very dangerous magick, "there's a ritual here, see, it changes your bloodline into someone else's, so you can switch Jimmy Novak's blood with mine and then hop into me - "

"Sam, no." Castiel did not fear that the ritual would be unsuccessful; old magick was generally too successful for its purpose. It was something else that unsettled him, something unidentifiable. Sam looked crestfallen, golden eyes glowing with intent.

"Please, Cas," he said, stepping very close. His face was mere inches away from Castiel's own, lips parted and breath puffing. His eyes were half-hooded, long lashes brushing against his skin. "Please." His voice was soft, pleading. "You saved me. I want to give you everything - my power, myself, everything. Please," he begged a third time, and brushed his lips over Castiel's. "Let me repay you for everything you've done for me."

Some part of Castiel was aware that Sam was most likely manipulating him. He had seen Sam use this seduction on other angels and demons. That part of Castiel insisted that something was wrong, that _Sam_ was wrong, that _events should not have come to this._That same part was swiftly buried beneath a staggering wave of desire.

Sam was very powerful, and very beautiful, with all the graces of a king. He was born to rule, after all. The demons feared and respected him, the angels adored him. Castiel wanted that for himself, so he could defeat Raphael and bring Heaven under his control.

Castiel agreed to Sam's plan.

The ritual was a simple affair: words, incense, the mixing of blood, and intercourse on an altar. Laying with Sam had been an intense, exhilarating experience - he had been very responsive, opening to Castiel easily and eagerly, clutching at the angel's shoulders and clenching with each thrust, "Cas" and "please" and "yours," falling from his lips. "Take me, take all of me, I give it to you freely," he panted, and Castiel took what was offered to him, drank down his power.

It filled him to the brim, electricity crackling around the tips of his wings. He left Jimmy Novak behind, and dove into Sam Winchester.

Sam was a fine vessel, the muscles and sinews of his body easily bending to Castiel's will. The power of the Boy King sparked through his heart, wrapping around his spine and flooding his nerves. Combined with Castiel's grace, it was more than enough to take down Raphael. "Sam," he said, voice no longer gravelly, but smooth, soft, and compelling, "I promise to return your body to you after the war has ended." He felt Sam's soul pulse happily in response.

Castiel supposed that the war could take longer than either of them anticipated. Perhaps he did not triumph over Raphael, and they were both killed. Perhaps Castiel would need Sam's power in the days to come, to keep Raphael's followers in line. He was no longer certain he would be able to fulfill his promise to Sam.

No matter. Sam certainly seemed more than willing to give up his body for Castiel's purpose. Surely he would not mind Castiel keeping it for an indefinite period of time.

Castiel flew off to gather his forces. He would stop Raphael, save the Earth, and he and Sam would protect it. Together. Forever.


End file.
